List<HashMap<String,Object>> list = new org.codehaus.jackson.map.ObjectMapper().readValue("[{"cpu":"2核","machineName":"r5.large","memory":"16G","price":35.040008544921875}]", ArrayList.class);
System.out.println(list.get(0).get("machineName")+"");

或者：JSON.parseArray(JSON.toJSONString(map.get("serverNameFilters")), String.class);